Download Additional Images

Additional Image Set for 2007
Science Olympiad
http://eezway.org/clinic/Astronomy/Addnl_Card_set.pdf
35. DEM L316: Supernova Remnants Deconstructed
•
This composite X-ray (red and
green)/optical (blue) image reveals
a cat-shaped image produced by
the remnants of two exploded
stars in the Large Magellanic
Cloud galaxy. Although the shells
of hot gas appear to be colliding,
this may be an illusion.
Chandra X-ray spectra show that
the hot gas shell on the upper left
contains considerably more iron
than the one on the lower right.
The high abundance of iron
implies that this supernova
remnant is the product of a Type Ia
supernova triggered by the infall of
matter from a companion star onto
a white dwarf star.
http://chandra.harvard.edu/photo/2005/d316/index.html
36. Globular Cluster 47 Tucanae
•
Stars come in bunches. Of the
over 200 globular star clusters
that orbit the center of our
Milky Way Galaxy, 47 Tucanae
is the second brightest
globular cluster (behind
Omega Centauri). Known to
some affectionately as 47 Tuc
or NGC 104, it is only visible
from the Southern
Hemisphere. Light takes about
20,000 years to reach us from
47 Tuc which can be seen
near the SMC in the
constellation of Tucana. Red
Giant stars are particularly
easy to see in the above
photograph. The dynamics of
stars near the center of 47 Tuc
are not well understood,
particularly why there are so
few binary systems there.
http://antwrp.gsfc.nasa.gov/apod/ap970919.html
37. Artist illustration – binary w/
accretion disk
• Transfer of mass occurs
in a binary star system.
Matter flows from a
sunlike star, in the
background in this
illustration, to a disk
orbiting a white dwarf
star, then to the surface
of the dwarf. Image
credit: Space Telescope
Science Institute
http://www.nasa.gov/worldbook/star_worldbook.html
•
•
The unusual nova shell GK Per is the
result of Nova Persei 1901, a nova
which exploded in 1901 about 1500
light-years away in the direction of the
constellation Perseus. Classical novae,
nowadays categorized as cataclysmic
variables, normally comprise a hot
white dwarf with accretion disk, and a
cool mass-transferring companion. At
some point, hydrogen burning triggers
thermonuclear runaway in the accreted
matter, leading to an explosive shock
wave and an expanding shell.
The first bright nova of the 20th century
and the first to be subjected to detailed
spectroscopy and photometry, Nova
Persei 1901 reached a maximum
brightness of 0.2m and declined very
rapidly thereafter to its current minimum
of 13.1. GK Per is unique among
classical novae, having the longest
known period (almost two days) and
showing dwarf nova-like outbursts of
about 3 mag. It also contains an
evolved secondary (type K2IV), while
all others have main sequence
companions.
38. GK Per
WIYN Image/NOAO
39. M42 – Orion Nebula
•
•
The nebula's glowing gas
surrounds hot young stars
at the edge of an immense
interstellar molecular cloud
only 1,500 light-years
away. The Orion Nebula
offers one of the best
opportunities to study how
stars are born partly
because it is the nearest
large star-forming region,
but also because the
nebula's energetic stars
have blown away obscuring
gas and dust clouds that
would otherwise block our
view - providing an intimate
look at a range of ongoing
stages of starbirth and
evolution.
The image spans 13 light
years
Hubble image
40. artist illustration, binary w/
accretion disk
41. Light Curve for
Algol Beta Persei
(typical eclipsing binary
system)
• The Algol, or Beta Persei,
compact triple-star system is
located around 92.8 lightyears (ly) from Sol
(HIPPARCOS Plx of 35.14, +/e_Plx of 0.90 mas). The star
lies in the west central part
(3:8:10.1+40:57:20.3, ICRS
2000.0) of Constellation
Perseus (see chart and
photo), the mythical Greek
Hero who uses the Gorgon
Medusa's severed head to
change Cetus into stone -southwest of Mirfak (Alpha
Persei). Among others, the
Ancient Greeks referred to
Algol as the "evil eye" of
Medusa probably because of
its regularly changing
www.aavso.org
brightness and color.
http://www.solstation.com/stars2/algol3.htm
Algol Beta Persei
Eclipsing Binary
42.RR Lyrae type of
variable star light curve
• RR Lyrae stars are pulsating
variables. The radial oscillations
of a pulsating star are the result of
waves (like sound waves)
resonating in the star's interior.
• All RR Lyrae stars are low-mass
horizontal branch stars in the core
helium burning stage of evolution.
• RR Lyraes all have about the
same brightness, and follow a
period-luminosity relation
Figure 1. The differing
light curve shapes of
RR Lyrae stars of Bailey
type a, b, and c.
Credit: RR Lyrae Stars,
H.Smith, Figure 1.1, p.3
http://www.aavso.org/vstar/vsots/0802.shtml
43. Z Cam light curve
• Z Cam is the prototype star of a subclass of dwarf nova-type
cataclysmic variables. The Z Camelopardalis stars are especially
known for their random standstills. Z Cam outbursts are classified into
three main categories - common, plateau, and anomalous - based on
the shape and duration of the outburst. Plateau outbursts are brighter
and last longer than common outbursts. Some outbursts end in
standstills in which the brightness stays constant roughly 1 mag
below maximum light for a few days to 1,000 days.
http://www.aavso.org/vstar/vsots/0499.shtml
44. SS Cygni light curve
• SS Cygni is a cataclysmic variable star, of the dwarf nova class.
Such variables are comprised of a close binary system with a white
dwarf primary star and a red dwarf secondary star, as mentioned
above. Due to the evolution of the system, the main sequence star
loses matter which is streamed in the direction of the primary,
forming an accretion disk around the white dwarf star. The
observed outbursts are believed to be the result of processes that
arise in the hydrogen-rich disk.
http://www.aavso.org/vstar/vsots/0600.shtml
45. Artist illustration of binary
system
46. Nova Cyg 1972 Light Curve
• In 1992 a tremendous explosion
occurred in the constellation of
Cygnus. Dubbed Nova Cygni 1992,
this event most probably occurred
in an accretion disk binary system.
Astronomers hypothesize that this
system's white dwarf had so much
gas dumped onto it's surface that
conditions became ripe for nuclear
fusion. The resulting thermonuclear
detonation blasted much of the
surrounding gas into an expanding
shell. The Hubble Space Telescope
photographed this expanding shell
in 1994. Nova Cygni 1992 was the
brightest nova in recent history - at
its brightest it could be seen without
a telescope. It was observed in
every part of the electromagnetic
spectrum.
http://antwrp.gsfc.nasa.gov/apod/ap951227.html
47. Betelgeuse
• First star seen as a sphere instead of a
point of light by the Hubble Space
Telescope on March 3, 1995.
• 12th brightest star in the sky .
• Possibly will be the very next
supernova.
• Type of Star:Orange-Red Supergiant
(M2 Iab Spectral Class).
• 3300K surface temp.
• Over 300 light years away
• 1300 times the sun's diameter. Would
overfill the orbit of Jupiter if placed at
the sun's position in the solar system
• 54,000 times the sun's visual
luminosity (absolute visual magnitude,
Mv = -7)
• 2nd brightest star In the constellation
of Orion (Star Map)
48. Nova Aquila
Light curve
•
•
The word nova is used to describe a star
that suddenly increases in brightness,
producing one, vivid maximum. Often
times there is no bright precursor to the
occurence, hence the Latin-based word
meaning "new" seems appropriate to
describe such events.
Novae belong to the class of stars
known as the Cataclysmic Variable (CV)
stars, along with the dwarf novae,
recurrent novae, nova-like, and polar
(magnetic) variables. And like all CVs,
the physical system is comprised of a
very close binary pair, with a white dwarf
star as the primary component and a
Sun-like, main sequence star as the
secondary.
http://www.aavso.org/vstar/vsots/0501.shtml
49. Mz3 – The Ant Nebula
•
Planetary nebula Mz3 is being
cast off by a star similar to our
Sun that is, surely, round. Why
then would the gas that is
streaming away create an antshaped nebula that is distinctly
not round? Clues might include
the high 1000-kilometer per
second speed of the expelled
gas, the light-year long length of
the structure, and the magnetism
of the star visible above at the
nebula's center. One possible
answer is that Mz3 is hiding a
second, dimmer star that orbits
close in to the bright star. A
competing hypothesis holds that
the central star's own spin and
magnetic field are channeling the
gas.
http://antwrp.gsfc.nasa.gov/apod/ap050501.html
50. Beta Lyrae
•
Beta Lyrae is a half separated (i.e. one of
the stars reached its Roche volume)
eclipsing binary of a cream-white color.
The brightness varies from 3.4 mag to 4.3
mag every twelve days and 22 hours. One
of the two stars of this system is filling its
Roche surface and ellipsoidally deformed.
Beta Lyrae is the prototype of this class of
eclipsing binaries, the Beta Lyrae Stars or
EB variables. For Sheliak, the larger star
totally eclipses its smaller companion in its
main minimum, while after half the period,
the smaller star occults parts of the larger
one to generate a secondary minimum of
about mag 3.8. Otto Struve interpreted
slight changes of its lightcurve as
indication for a disk of dark matter
surrounding the secondary star - very
probably forming streams of hot gas
ejected by the gravitationally interacting
stars.
http://www.seds.org/~spider/spider/Vars/betaLyr.html
51. T Tauri light curve
•
T Tauri stars are named for the prototype of the class, T Tauri. These objects
are pre-main sequence stars and have recently emerged from the opaque
envelope of stellar formation. Having recently coalesced from their dusty and
gaseous surroundings, these stars now become visible at optical
wavelengths. The clouds of dust and gas that condense are composed of
mainly Hydrogen, some Helium, and some other trace elements.
http://www.aavso.org/vstar/vsots/0201.shtml
52. Cepheus
53. Betelgeuse light curve
• The linked light curve shows monthly means for the years 1988-96.
Poor weather in late 1995 / early 1996 restricted the number of
estimates made and contributed to the scatter, but it seems that
Betelgeuse stayed near maximum during 1996 and possibly
brightened slightly.
http://www.popastro.com/sections/vs/vss1997.htm
Mz3 – The Ant Nebula
• From ground-based
telescopes, the so-called "ant
nebula" (Menzel 3, or Mz 3)
resembles the head and
thorax of a garden-variety ant.
This dramatic NASA/ESA
Hubble Space Telescope
image, showing 10 times more
detail, reveals the "ant's" body
as a pair of fiery lobes
protruding from a dying, Sunlike star.
Credit: Hojoe & the ESA/ESO/NASA Photoshop FITS Liberator